Am Donnerstag, 5. März 2009 13:09 schrieb Peter Verswyvelen:
> Ha. There's even a wiki page on the paradoxes of set theory
>http://en.wikipedia.org/wiki/Paradoxes_of_set_theory>> If I recall correctly, a math professor once told me that it is not yet
> proven if the cardinality of the power set of the natural numbers is larger
> or smaller or equal than the cardinality of the real numbers... But that
> is many many years ago so don't shoot me if I'm wrong :)
>
In standard NBG set theory, it is easy to prove that card(P(N)) == card(R).